scholarly journals Atomic force microscopy in the assessment of erythrocyte membrane mechanical properties with exposure to various physicochemical agents

2021 ◽  
Vol 49 (6) ◽  
pp. 427-434
Author(s):  
E. A. Sherstyukova ◽  
V. A. Inozemtsev ◽  
A. P. Kozlov ◽  
O. E. Gudkova ◽  
V. A. Sergunova
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Erythrocyte Membrane ◽  
Uv Radiation ◽  
Structural Organization ◽  
Young's Modulus ◽  
Homogeneous Medium ◽  
Topological Defects ◽  
Erythrocyte Membranes ◽  
Atomic Force

Background: Mechanical properties of cell membranes and their structural organization are considered among the most important biological parameters affecting the functional state of the cell. Under the influence of various pathogenic factors, erythrocyte membranes lose their elasticity. The resulting changes in their biomechanical characteristics is an important, but poorly studied topic. It is of interest to study the deformation of native erythrocytes to a depth compatible with their deformation in the bloodstream.Aim: To investigate the patterns of deep deformation and the particulars of structural organization of native erythrocyte membranes before and after their exposure to physicochemical agents in vitro.Materials and methods: Cell morphology, nanostructure characteristics, and membrane deformation of native erythrocytes in a  solution of hemoconservative CPD/SAGM were studied with atomic force microscope NTEGRA Prima. Hemin, zinc ions (Zn2+), and ultraviolet (UV) radiation were used as modifiers. To characterize the membrane stiffness, we measured the force curves F(h), hHz (the depth to which the probe immersion is described by interaction with a homogeneous medium), and the Young's modulus values of the erythrocyte membrane.Results: Exposure to hemin, Zn2+ and UV radiation led to transformation of the cell shape, appearance of topological defects and changes in mechanical characteristics of erythrocyte membranes. Under exposure to hemin, Young's modulus increased from 10±4  kPa to 27.2±8.6  kPa (p<0.001), exposure to Zn2+, to 21.4±8.7  kPa (p=0.002), and UV, to 18.8±5.6  kPa (p=0.001). The hHz value was 815±210  nm for the control image and decreased under exposure to hemin to 420±80 nm (p<0.001), Zn2+, to 370±90 nm (p<0.001), and UV, to 614±120 nm (p=0.001).Conclusion: The results obtained contribute to a  deeper understanding of interaction between membrane surfaces of native erythrocytes and small vessel walls. They can be useful in clinical medicine as additional characteristics for assessment of the quality of packed red blood cells, as well as serve as a basis for biophysical studies into the mechanisms of action of oxidative processes of various origins.

scholarly journals Characterisation of the Material and Mechanical Properties of Atomic Force Microscope Cantilevers with a Plan-View Trapezoidal Geometry

2019 ◽  
Vol 9 (13) ◽  
pp. 2604 ◽  
Author(s):  
Ashley D. Slattery ◽  
Adam J. Blanch ◽  
Cameron J. Shearer ◽  
Andrew J. Stapleton ◽  
Renee V. Goreham ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscope ◽  
Young’S Modulus ◽  
Correction Factor ◽  
Young's Modulus ◽  
Spring Constant ◽  
Beam Equation ◽  
Euler Beam ◽  
Plan View ◽  
Atomic Force

Cantilever devices have found applications in numerous scientific fields and instruments, including the atomic force microscope (AFM), and as sensors to detect a wide range of chemical and biological species. The mechanical properties, in particular, the spring constant of these devices is crucial when quantifying adhesive forces, material properties of surfaces, and in determining deposited mass for sensing applications. A key component in the spring constant of a cantilever is the plan-view shape. In recent years, the trapezoidal plan-view shape has become available since it offers certain advantages to fast-scanning AFM and can improve sensor performance in fluid environments. Euler beam equations relating cantilever stiffness to the cantilever dimensions and Young’s modulus have been proven useful and are used extensively to model cantilever mechanical behaviour and calibrate the spring constant. In this work, we derive a simple correction factor to the Euler beam equation for a beam-shaped cantilever that is applicable to any cantilever with a trapezoidal plan-view shape. This correction factor is based upon previous analytical work and simplifies the application of the previous researchers formula. A correction factor to the spring constant of an AFM cantilever is also required to calculate the torque produced by the tip when it contacts the sample surface, which is also dependent on the plan-view shape. In this work, we also derive a simple expression for the torque for triangular plan-view shaped cantilevers and show that for the current generation of trapezoidal plan-view shaped AFM cantilevers, this will be a good approximation. We shall apply both these correction factors to determine Young’s modulus for a range of trapezoidal-shaped AFM cantilevers, which are specially designed for fast-scanning. These types of AFM probes are much smaller in size when compared to standard AFM probes. In the process of analysing the mechanical properties of these cantilevers, important insights are also gained into their spring constant calibration and dimensional factors that contribute to the variability in their spring constant.

scholarly journals Alteration of nanomechanical properties of pancreatic cancer cells through anticancer drug treatment revealed by atomic force microscopy

2021 ◽  
Vol 12 ◽  
pp. 1372-1379
Author(s):  
Xiaoteng Liang ◽  
Shuai Liu ◽  
Xiuchao Wang ◽  
Dan Xia ◽  
Qiang Li
Keyword(s):  
Mechanical Properties ◽  
Pancreatic Cancer ◽  
Atomic Force Microscopy ◽  
Cancer Cells ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Force Microscopy ◽  
Pancreatic Cancer Cells ◽  
Atomic Force ◽  
Aggressive Cancer

The mechanical properties of cells are key to the regulation of cell activity, and hence to the health level of organisms. Here, the morphology and mechanical properties of normal pancreatic cells (HDPE6-C7) and pancreatic cancer cells (AsPC-1, MIA PaCa-2, BxPC-3) were studied by atomic force microscopy. In addition, the mechanical properties of MIA PaCa-2 after treatment with different concentrations of doxorubicin hydrochloride (DOX) were also investigated. The results show the Young's modulus of normal cells is greater than that of three kinds of cancer cells. The Young's modulus of more aggressive cancer cell AsPC-1 is smaller than that of less aggressive cancer cell BxPC-3. In addition, the Young's modulus of MIA PaCa-2 rises with the increasing of DOX concentration. This study may provide a new strategy of detecting cancer, and evaluate the possible interaction of drugs on cells.

scholarly journals Atomic Simulation of Nanoindentation on the Regular Wrinkled Graphene Sheet

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1127
Author(s):  
Ruonan Wang ◽  
Haosheng Pang ◽  
Minglin Li ◽  
Lianfeng Lai
Keyword(s):  
Mechanical Properties ◽  
Boundary Condition ◽  
Boundary Conditions ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Md Simulations ◽  
Force Microscopy ◽  
Atomic Simulation ◽  
Atomic Force ◽  
Surface Wrinkling

Surface landscapes have vague impact on the mechanical properties of graphene. In this paper, single-layered graphene sheets (SLGS) with regular wrinkles were first constructed by applying shear deformation using molecular dynamics (MD) simulations and then indented to extract their mechanical properties. The influence of the boundary condition of SLGS were considered. The wrinkle features and wrinkle formation processes of SLGS were found to be significantly related to the boundary conditions as well as the applied shear displacement and velocity. The wrinkling amplitude and degree of wrinkling increased with the increase in the applied shear displacements, and the trends of wrinkling wavelengths changed with the different boundary conditions. With the fixed boundary condition, the degree of graphene wrinkling was only affected when the velocity was greater than a certain value. The effect of wrinkles on the mechanical characterization of SLGS by atomic force microscopy (AFM) nanoindentation was finally investigated. The regular surface wrinkling of SLGS was found to weaken the Young’s modulus of graphene. The Young’s modulus of graphene deteriorates with the increase in the degree of regular wrinkling.

Microscopic Methods for Characterization of Selected Surface Properties of Biodegradable, Nanofibrous Tissue Engineering Scaffolds

2017 ◽  
Vol 890 ◽  
pp. 213-216 ◽  
Author(s):  
Adrian Chlanda ◽  
Ewa Kijeńska ◽  
Wojciech Święszkowski
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Force Spectroscopy ◽  
Operating Mode ◽  
Tissue Engineering Scaffolds ◽  
Force Microscopy ◽  
Atomic Force

Biodegradable polymeric fibers with nanoand submicron diameters, produced by electrospinning can be used as scaffolds in tissue engineering. It is necessary to characterize their mechanical properties especially at the nanoscale. The Force Spectroscopy is suitable atomic force microscopy mode, which allows to probe mechanical properties of the material, such as: reduced Young's modulus, deformation, adhesion, and dissipation. If combined with standard operating mode: contact or semicontact, it will also provide advanced topographical analysis. In this paper we are presenting results of Force Spectroscopy characterization of two kinds of electrospun fibers: polycaprolactone and polycaprolactone with hydroxyapatite addition. The average calculated from Johnson-Kendall-Roberts theory Young's modulus was 4 ± 1 MPa for pure polymer mesh and 20 ± 3 MPa for composite mesh.

Microstructure and Mechanical Properties of TiN/NbN Multilayered Coating

2010 ◽  
Vol 434-435 ◽  
pp. 466-468
Author(s):  
Chien Cheng Liu ◽  
Kuang I Liu ◽  
Huai Wei Yan ◽  
Chia Li Ma ◽  
Jow Lay Huang
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Steel Ball ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pin On Disk ◽  
Heating Up ◽  
Steel Substrates ◽  
Stylus Profiler

In this study, multilayers of TiN/NbN were deposited by d.c. magnetron sputtering on die steel substrates. The structure, morphology and nano-hardness were assessed using X-ray diffraction, atomic force microscopy (AFM), stylus profiler (XP-2 stylus profiler) and nanoindentation, respectively. Wear tests were performed on pin-on-disk configuration and dry sliding conditions, at 5N load by using hardened steel ball. The result shows TiN with highly (111) preferred orientation. On mechanical properties, Young’s modulus and hardness values increase for layers number increase. At 64 layers films had the highest nano-hardness, Young’s modulus values. The TiN/NbN multilayer films presented changes in its morphology becoming more granulated and density after heating up to 500°C. A significant decrease in friction coefficient has been achieved for TiN/NbN multilayers against steel ball.

Mechanical Properties of Poly 3C-SiC Thin Films According to Carrier Gas (H2) Concentration

2008 ◽  
Vol 600-603 ◽  
pp. 867-870
Author(s):  
Gwiy Sang Chung ◽  
Ki Bong Han
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Surface Roughness ◽  
Atomic Force Microscope ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Carrier Gas ◽  
Nano Indentation ◽  
Atomic Force

This paper presents the mechanical properties of 3C-SiC thin film according to 0, 7, and 10 % carrier gas (H2) concentrations using Nano-Indentation. When carrier gas (H2) concentration was 10 %, it has been proved that the mechanical properties, Young’s Modulus and Hardness, of 3C-SiC are the best of them. In the case of 10 % carrier gas (H2) concentration, Young’s Modulus and Hardness were obtained as 367 GPa and 36 GPa, respectively. When the surface roughness according to carrier gas (H2) concentrations was investigated by AFM (atomic force microscope), when carrier gas (H2) concentration was 10 %, the roughness of 3C-SiC thin was 9.92 nm, which is also the best of them. Therefore, in order to apply poly 3C-SiC thin films to MEMS applications, carrier gas (H2) concentration’s rate should increase to obtain better mechanical properties and surface roughness.

Structural and mechanical properties of a-axis AlN thin films growth using reactive RF magnetron sputtering plasma

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anis Suhaili Bakri ◽  
Nafarizal Nayan ◽  
Chin Fhong Soon ◽  
Mohd Khairul Ahmad ◽  
Ahmad Shuhaimi Abu Bakar ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Magnetron Sputtering ◽  
Young’S Modulus ◽  
Plasma Deposition ◽  
Young's Modulus ◽  
Rf Magnetron Sputtering ◽  
Content Type ◽  
Sputtering Deposition ◽  
Atomic Force

Purpose This paper aims to report the influence of sputtering plasma deposition time on the structural and mechanical properties of the a-axis oriented aluminium nitride (AlN) thin films. Design/methodology/approach The AlN films were prepared using RF magnetron sputtering plasma on a silicon substrate without any external heating with various deposition times. The films were characterized using X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), atomic force microscope (AFM) and nanoindentation techniques. Findings The XRD results show that the AlN thin films are highly oriented along the (100) AlN plane at various deposition times indicating the a-axis preferred orientation. All the AlN thin films exhibit hexagonal AlN with a wurtzite structure. The hardness and Young’s modulus of AlN thin films with various deposition times were measured using a nanoindenter. The measured hardness of the AlN films on Si was in the range of 14.1 to 14.7 GPa. The surface roughness and the grain size measured using the AFM revealed that both are dependent on the deposition times. Originality/value The novelty of this work lies with a comparison of hardness and Young’s modulus result obtained at different sputtering deposition temperature. This study also provides the relation of AlN thin films’ crystallinity with the hardness of the deposited films.

scholarly journals Homogeneous Deformation of Native Erythrocytes During Long-Term Storage

2019 ◽  
Vol 15 (5) ◽  
pp. 4-10 ◽  
Author(s):  
E. A. Manchenko ◽  
E. K. Kozlova ◽  
V. A. Sergunova ◽  
A. M. Chernysh
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Homogeneous Medium ◽  
Fold Increase ◽  
Interaction Force ◽  
Erythrocyte Membranes ◽  
Erythrocyte Suspension ◽  
Theoretical Dependence ◽  
Long Term Storage

Purpose of the study — to evaluate biomechanical regularities of deep deformation of native erythrocytes’ membranes during long-term (up to 32 days) storage of erythrocyte suspension.Materials and methods. The method for addressing the said problem was atomic-force spectroscopy. The measured value was hHz comprizing the depth to which the probe immersion process was described by interaction with a homogeneous medium. Empirical and theoretical dependence of the interaction force F (nN) on the probe immersion depth h (nm) — F (h) were obtained. Bar charts of relative frequency density of Young’s modulus E were built.Results. Modulus E changed from 9.3±3.2 kPa — for 3 days of storage, to 22.7±8.7 kPa — for 32 days. Coefficients of skewness were 0.52±0.04 (for day 3) and 0.82±0.09 (for day 32 d), hHz value remaining constant.Conclusion. Progressively as erythrocyte suspension was stored, erythrocyte membranes to the depth of 700 nm deflected homogeneously in spite of 2.4-fold increase of Young’s modulus.

Accurate determination of the mechanical properties of thin aluminum films deposited on sapphire flats using nanoindentations

1999 ◽  
Vol 14 (6) ◽  
pp. 2314-2327 ◽  
Author(s):  
Y. Y. Lim ◽  
M. M. Chaudhri ◽  
Y. Enomoto
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Accurate Determination ◽  
Direct Methods ◽  
Polycrystalline Aluminum ◽  
Aluminum Films ◽  
Force Microscopy ◽  
Contact Areas ◽  
Atomic Force

Nanoindentations using a Berkovich diamond indenter have been made on 1, 2, and 5 μm thick 99.99% purity polycrystalline aluminum films thermally evaporated in vacuum on to 2 mm thick R-cut polished sapphire flats. The projected contact areas of the residual indentations were estimated from the unloading load-displacement curves, and some of the indentations were imaged with an atomic force microscope (AFM). It was found that a large majority of indents showed material pileup, and the projected areas of these indents, as measured with the AFM, were up to 50% greater than those calculated from the unloading curves. This discrepancy between the calculated and directly measured indentation areas has a strong influence on the derived values of Young's modulus and hardness of the aluminum films. Using a new analytical model, Young's modulus of the aluminum films has been determined to be in the range of 50–70 GPa, independent of the relative indentation depth. The composite nanohardness of the 1 and 2 μm thick films was found to have a load-independent value of 1 GPa, whereas the composite nanohardness of the 5 μm film decreased from 1 to 0.7 Gpa with increasing indenter penetration. Finally, it has been suggested that in order to improve the accuracy with which the mechanical properties of thin films or bulk specimens can be determined by nanoindentation techniques, the projected contact areas should be measured by direct methods, such as atomic force microscopy.

scholarly journals Evaluation methods of mechanical properties for low-k dielectrics

2021 ◽  
Vol 9 (3) ◽  
pp. 40-48
Author(s):  
I. S. Ovchinnikov
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Dielectric Constant ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Low Dielectric Constant ◽  
Insulating Materials ◽  
Force Microscopy ◽  
Low Dielectric ◽  
Atomic Force

This review introduces the study of state-of-art methods for assessing the mechanical properties of insulating materials with low dielectric constant. The main features of measuring Young’s modulus of thin films insulating materials with low dielectric constant are determined by usage of Brillouin light scattering, surface acoustic wave spectroscopy, picosecond laser-acoustic method, ellipsometric porosimetry, nanoindentation and atomic force microscopy in various modes. The author estimated the optimum lateral and optimum depth resolution for each above method. The review analyzes the degree of sample preparation complexity for the measurements by these methods and describes what methods of measurement are destructive for the samples. Besides, the review makes a comparison for the results of evaluating Young’s modulus of insulating materials with low dielectric constant achieved by different methods. Comparative analysis of the methods for assessing mechanical properties lead us to the conclusion that the method of atomic force microscopy is superior to other methods described above, both in lateral (8 nm) and optimum depth (10 nm) resolution. It is shown that due to the small impact force of the atomic force microscope probe on the surface, the method does not have a destructive effect on the sample. In addition, there is no need to create special conditions for the experiment (e.g., the cleanliness level of the premises, the possibility of an experiment under environmental conditions, etc.). This makes the experiment relatively simple in terms of preparing the object of research. It has been also established that the method of atomic force microscopy in the mode of quantitative nanomechanical mapping allows forming a map of the distribution of the Young’s modulus of the insulating material as part of the metallization system of integrated circuits.

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